Have tested this in both Win7 and Win10 x64 environments. Using FCXE64 v764.

I use saved layouts frequently. Some are dual-pane (horizontal), others are single pane. With v764 (and v763 too), the following behaviour occurs:

If the opening layout is set to a custom single-pane one, it opens fine. And when I then switch to a dual-pane horizontal layout, that's fine too. However, upon switching back to a custom single-pane, the bottom "pane" becomes a very fat/thick status bar which basically takes up the entire space just recently occupied by the bottom pane in the previous dual-pane horizontal layout. If this custom single-pane layout (which has already been re-selected) is selected yet again, then the problem goes away.

The same problem occurs if the opening layout is set to a custom dual-pane horizontal one. When I then switch to a single pane layout, the fat/thick status bar phenomenon also occurs.

I have an update on this issue. (Marek, I assume you are already aware, but I'm just posting it for other forum members.)

Originally my problem was revealed while switching from a custom horizontal dual-pane to a custom single-pane layout. I finally got a chance to also test it by switching from a custom vertical dual-pane setup. That results in the right half of the single-pane layout to be a grey block (which does _not_ seem to be the status bar).

So the reason for my second post is that I mis-named the subject line of my original bug report post. It's not just a status-bar issue, but one which a "ghost" from a former dual pane layout blocks half of the now-selected single pane layout.